Papers by Keyword: Ultrasonic Vibration

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Authors: Yong Bo Wu, Li Jun Wang
Abstract: Chemical mechanical polishing (CMP) is often employed to obtain a super smooth work-surface of a silicon wafer. However, as a conventional CMP is a loose abrasive process, it is hard to achieve the high profile accuracy and lots of slurry must be supplied during CMP operations. As an alternate solution, a fixed abrasive CMP process can offer better geometrical accuracy and discharges less waste disposal. In this paper, in order to enhance the polishing efficiency and improve the work-surface quality, a novel ultrasonic assisted fixed abrasive CMP (UF-CMP) is proposed and the fundamental machining characteristics of the UF-CMP of a silicon wafer is investigated experimentally. The results show that with the ultrasonic assistance, the material removal rate (MRR) is increased, and the surface quality is improved.
Authors: Yong Bo Wu, Yu Feng Fan, M. Kato, Jun Wang, Katsuo Syoji, Tsunemoto Kuriyagawa
Authors: Ji Cai Kuai
Abstract: The embedded transducer structure is used to put the transducer into the inside of the honing oil stone bed, which is directly driven by the transducer to vibrate and carry out the ultrasonic honing. Experiments show that honing efficiency of the device lowers by 50%, the roughness of honing surface Ra reaches 60nm - 30nm and the cylindricity comes to 10μm - 1μm, which is much higher than the traditional ultrasonic honing precision. This method solves a range of issues of complex structure, high manufacturing costs, not suitable for ultra-precise honing of the traditional ultrasonic honing head, and it is simple to process and easy to install with low manufacturing costs. Because there is no amplifying of horn, the amplitude is very small, which is especially suitable for ultra-precision honing.
Authors: L.G. Chen, L.N. Sun, Y.X. Liu, H.X. Wang
Abstract: Molecular techniques are transforming our understanding of cellular function and disease. However, accurate molecular analysis methods will be limited if the input DNA, RNA, or protein is not derived from pure population of cells or is contaminated by the wrong cells. A novel Ultrasonic Vibration Microdissection (UVM) method was proposed to procure pure population of targeted cells from tissue sections for subsequent analysis. The principle of the Ultrasonic Vibration Cutting is analyzed, and a novel microknife is designed. A multilayer piezoelectric actuator is used to actuate a sharp needle vibrating with high frequency and low amplitude (Approx. 16–50 kHz, and 0-3μm) to cut the tissue. Contrast experiment was done to test the feasibility of UVM method. Experimental results show that the embedded tissue can be quickly and precisely cut with the ultrasonic vibration micro-dissection method.
Authors: Ya Xin Liu, Ming Zhong, Li Guo Chen
Abstract: Micro-dissection technology possesses revolutionary significance in the research field about Cancer Genomics, through which pure population of targeted cells can be procured from tissue sections for subsequent analysis. In this paper, a novel Micro-dissection technology using ultrasonic vibration was proposed and the piezo-powered micro-dissection tool with its control and drive system were also developed. The micro-dissection tool employs the multilayer piezoelectric actuator for generating the ultrasonic vibration with high frequency and low amplitude. To control the piezo-powered Micro-dissection tool, a driving power for piezoelectric actuator was designed using direct digital synthesizer and direct current amplifying principle, thus the micro-dissection tool could vibrate with the frequency scope from 0.5k to50K and the amplitude scope from 0 to 2μm. Finally, experiments about bio-microdissection on liver tissue slice were carried out with the tool and better micro-dissection result was obtained. The experiments show the feasibility of the micro-dissection method with ultrasonic vibration. The new micro-dissection method can be adopted in the bio-micro-manipulation field and it can also significantly promote the development of Cancer Genomics.
Authors: Ho Dong Yang, Yool Kwon Oh
Abstract: The present study was experimentally investigated the effect of ultrasonic vibrations on boiling heat transfer augmentation during the heating process. The experiments were carried out under the constant wall temperature condition and were divided into two cases applying with and without ultrasonic vibrations, respectively. Also, the temperature distributions in a vessel filled with water were measured using thermocouples during the heating process, heat transfer coefficient and augmentation ratio of heat transfer on states of convection, subcooled boiling and saturated boiling were calculated from obtained temperature profiles. In addition, the profiles of pressure variations measured using a hydrophone were compared with the augmentation ratio of heat transfer in acoustic fields. The results of experimental study were revealed that general profiles of heat transfer coefficient and augmentation ratio of heat transfer is more increased the convection state than the others states. Moreover, the profiles of acoustic pressure is relatively higher near ultrasonic transducer than other points where is no installed it and affects the augmentation ratio of heat transfer. In the end, as well as known “acoustic streaming” induced by ultrasonic vibrations is one of the prime effects acoustically augmented boiling heat transfer or phase change heat transfer.
Authors: Xue Hui Shen, Jian Hua Zhang, Tian Jin Yin, Chun Jie Dong
Abstract: The applications of micro end milling have been gradually broadened to meet the ever-increasing demands for micro parts. In micro milling, premature tool failure and short service life are major problems. In this study, micro end milling with ultrasonic vibration in normal direction is investigated. Kinematical analysis is done to describe the exact trajectory of the tool tip when vibration is applied. Based on which, an analytical model of chip formation is proposed. By accurate calculation of instantaneous chip thickness, the cutting forces in micro end milling with and without ultrasonic vibration are predicted and verified by a slot-milling experiment. As a result, it is found that ultrasonic vibration in normal direction is helpful when reducing the cutting force owing to intermittent cutting effect.
Authors: Zhong Wei Zhang, Hong Tao Zhu, Chuan Zhen Huang, Jun Wang, Peng Yao, Zeng Wen Liu
Abstract: Ultrasonic vibration-assisted machining (UVAM) is an effective and promising technology for processing hard and brittle materials, it has been explored in many experimental and theoretical investigations. In this paper, a study on the erosion performance of monocrystalline silicon with UVAM is presented and discussed. In the erosion experiments, monocrystalline silicon wafers were eroded by the abrasive water jet machine assisted with an ultrasonic vibration system. A contrast experiment was carried out firstly to study the influence of the ultrasonic vibration, and then an orthogonal experiment investigation was carried out to understand the effect of process variables (the abrasive particle diameter, jet impact angle, standoff distance, abrasive mass flow rate and ultrasonic vibration power) on the depth of erosion and material removal rate (MRR). The experimental results revealed that ultrasonic vibration-assisted abrasive water jet erosion (UVA-AWJE) can obviously improve the depth of the erosion and MRR compared with those in traditional AWJE and the variation trends of the effect of the abrasive particle diameter, jet impact angle, standoff distance and abrasive mass flow rate on the erosion performance in UVA-AWJE are very similar to those effect in the traditional AWJ machining.
Authors: Yan Xu, Wei Chen, Kai Leung Yung
Abstract: The most apparent advantages of thermoplastics are the recyclability and processibility. To obtain recyclable and injectable conductive polymer, this paper studied the filling of carbon nanotubes (CNT) in polystyrene(PS) and the aligning of CNT in PS under high frequency electric field and ultrasonic vibration using an experimental set up developed in our laboratory. Results of these studies would be very useful to the development of a new generation of micro fabrication method for producing integrated micro electronic products using micro injection molding that is the most cost effective way to produce micro products massively.
Authors: T. Ichitsubo, Eiichiro Matsubara, K. Anazawa, Nobuyuki Nishiyama, Makio Naito, Yoshihiko Hirotsu
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